Communication with segment routing in a cable modem network environment

ABSTRACT

An example system and method for facilitating communication with segment routing in a cable modem network environment is provided and includes receiving, at a remote physical device (RPD) in a network, a PW control packet including segment routing information including a PW segment identifier (PW SID) for establishing a data session between the RPD and a network element over a packet switched network, the PW SID indicative of a segment in the packet switched network to be used for communicating PW data packets of the data session, the PW control packet and the PW data packets being emulations of a point-to-point connection between the RPD and the network element, and writing into a segment table of the RPD a mapping between the PW SID and the data session. In specific embodiments, the network element comprises a Converged Cable Access Platform (CCAP) Core of a cable network.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of priority under 35 U.S.C. §119(e)to U.S. Provisional Patent Application Ser. No. 62/173,170, filed onJun. 9, 2015 and entitled DOWNSTREAM EXTERNAL PHYSICAL (PHY) INTERFACE(DEPI) WITH SEGMENT ROUTING OVER MULTI-PROTOCOL LABEL SWITCHING (MPLS)AND INTERNET PROTOCOL VERSION 6 (IPv6), the disclosure of which ishereby incorporated by reference in its entirety.

TECHNICAL FIELD

This disclosure relates in general to the field of communications and,more particularly, to communication with segment routing in a cablemodem network environment.

BACKGROUND

Driven by market evolution towards triple-play services, cable operatorsin emerging markets are seeking standardized and digital fiber-basedsolutions for economical and future proof access technologies. Much ofthe demand is driven by the need to provide higher bandwidth packettransport for Internet connectivity, video and voice services. Data OverCable Service Interface Specification (DOCSIS) is an internationaltelecommunications standard that has evolved to permit addition ofhigh-bandwidth data transfer to an existing cable TV (CATV) systemutilizing Quadrature Amplitude Modulation (QAM) and/or Quadraturephase-shift keying (QPSK) Radio Frequency (RF) modulation. It isemployed by many cable television operators to provide Internet accessover their existing hybrid fiber-coaxial (HFC) infrastructure.Traditionally, the DOCSIS system is a Point-to-Multipoint communicationssystem, the corresponding standards defining Media Access Control(MAC)/PHY standards associated with providing high speed data over ahybrid fiber coaxial (HFC) network and is not naturally applicable fordigital fiber. However, Cisco® remote-PHY (R-PHY) technology bridges thegap, for example, by allowing the optical part of the HFC plant to bedigital as well as to separate the PHY components from the CCAP andlocate them at the edge of the fiber plant.

BRIEF DESCRIPTION OF THE DRAWINGS

To provide a more complete understanding of the present disclosure andfeatures and advantages thereof, reference is made to the followingdescription, taken in conjunction with the accompanying figures, whereinlike reference numerals represent like parts, in which:

FIG. 1 is a simplified block diagram illustrating a communication systemfor communication with segment routing in a cable modem networkenvironment;

FIG. 2 is a simplified block diagram illustrating example details ofembodiments of the communication system;

FIG. 3 is a simplified block diagram illustrating other example detailsof embodiments of the communication system;

FIG. 4 is a simplified block diagram illustrating yet other exampledetails of embodiments of the communication system;

FIG. 5 is a simplified block diagram illustrating yet other exampledetails of embodiments of the communication system;

FIG. 6 is a simplified block diagram illustrating yet other exampledetails of embodiments of the communication system; and

FIG. 7 is a simplified flow diagram illustrating example operations thatmay be associated with an embodiment of the communication system.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS Overview

An example system and method for facilitating communication with segmentrouting in a cable modem network environment is provided and includesreceiving, at a remote physical device (RPD) in a network, a pseudowire(PW) control packet including segment routing information with a PWsegment identifier (PW SID) for establishing a data session between theRPD and a network element over a packet switched network, the PW SIDindicative of a segment in the packet switched network to be used forcommunicating PW data packets of the data session, the PW control packetand the PW data packets respectively carrying control information anddata, and comprising emulations of a point-to-point connection over thepacket switched network between the RPD and the network element, andwriting into a segment table of the RPD a mapping between the PW SID andthe data session. In specific embodiments, the network element is aConverged Cable Access Platform (CCAP) Core of a cable network.

In a general sense, “control information” comprises information forcontrolling data forwarding functions, including network routing paths,protocols, routing states, vendor and platform specific stacking,clustering, pairing and other such information; “data” refers to anytype of numeric, voice, video, or script data, or any other suitableinformation in any appropriate format that may be communicated over thenetwork as transit traffic in data sessions. Data and controlinformation are mutually exclusive types of information; for example,control information facilitates setting up network routes for forwardingdata.

EXAMPLE EMBODIMENTS

Turning to FIG. 1, FIG. 1 is a simplified block diagram illustrating acommunication system 10 for communication with segment routing inaccordance with one example embodiment. Communication system 10 includesa packet switched network 12, including a plurality of switches (androuters) 13 facilitating communication between a Converged Cable AccessPlatform (CCAP)-Core 14 and a remote physical device (RPD) 16. RPD 16communicates with one or more cable modem (CM) 18 over a hybridfiber-coaxial (HFC) network 20. A controller 22 in network 12communicates with RPD 16, providing certain network control planefunctions according to embodiments of communication system 10. Invarious embodiments, packet switched network 12 implements a labelswitched architecture running Segment Routing (SR).

CCAP-Core 14 and RPD 16 together comprise a combination of a DOCSIScable modem termination system (CMTS) and an edge QAM (EQAM). MediaAccess Control (MAC) and higher-layer functions of the CMTS are locatedin CCAP-Core 14, for example, including signaling functions, downstreambandwidth scheduling and DOCSIS framing. RPD 16 includes QAM modulatorsto connect to CM 18 over HFC network 20. RPD 16 has network (e.g.,Ethernet) interfaces on one side (e.g., connected to network 12) and RFinterfaces on the other side (e.g., connected to HFC network 20). RPD 16provides Layer 1 physical (PHY) conversion, Layer 2 MAC conversion, andLayer 3 pseudo-wire support.

CCAP-Core 14 and RPD 16 communicate over an interface supporting anInternet Protocol (IP) tunnel through network 12. The IP tunnel includesa data path for DOCSIS frames and control path for setting up,maintaining, and tearing down sessions between CCAP-Core 14 and RPD 16.Communication between RPD 16 and CCAP-Core 14 is facilitated throughdownstream external physical interface (DEPI) and Upstream ExternalPhysical Interface (UEPI). DEPI and UEPI are IP-based PW packetsinserted between a DOCSIS MAC in CCAP-Core 14 and a DOCSIS PHY in RPD16. UEPI is an extension to DEPI. UEPI uses the same control planestructure and a unique set of encapsulations in the upstream direction.DEPI facilitates transporting DOCSIS data (e.g., DOCSIS frames or videopackets (e.g., Moving Picture Experts Group (MPEG) packets)) formattedas PW packets through network 12 in the form of Layer 2 or Layer 3packets. Specifically, DOCSIS data destined to CM 18 is communicatedthrough network 12 using DEPI PW packets. In other words, DEPI operatesto take either of the formatted DOCSIS frames, transport them through aLayer 2 or Layer 3 network, and deliver them to RPD 16 for transmissionto CM 18. UEPI operates in the reverse direction, to take DOCSIS framesthat have been received at RPD 16 and demodulated by the DOCSIS upstreamPHY in RPD 16 and transport them to CCAP-Core 14 for processing. RPD 16does not provide any upstream DOCSIS processing.

In a general sense, the PW is a mechanism to transparently transport aLayer 2 protocol over a Layer 3 network. RFC 3955 defines the PW as anemulation of a point-to-point connection over a packet switched network.The PW allows the packet switched IP network to carry a service withoutthe service having to know details of the IP network; in other words,one transport is encapsulated in another transport, similar to an IPtunnel (however, a tunnel may contain one or more PWs). To build genericPW packets, a service is required for the PW to connect, and anunderlying protocol is required for transporting the PW packet. Examplesof underlying protocols are IP (e.g., for simple tunnels that do notrequire session setup), Multiprotocol Label Switching (MPLS) (e.g., forMPLS networks) and Layer 2 Tunneling Protocol Version 3 (L2TPv3) (e.g.,for IP networks with session setup).

L2TPv3 is the generic protocol used for creating DEPI/UEPI PW packets,which can be transported over MPLS or IPv6 networks. In variousembodiments, a Remote PHY PW module at CCAP-Core 14 facilitates settingup the PW channel (e.g., path) between CCAP-Core 14 and RPD 16 forcommunicating the DEPI PW packets over network 12. A Packet StreamingProtocol (PSP) module at CCAP-Core 14 generates the DEPI PW packets. Ina general sense, the PSP module encapsulates a continuous stream ofDOCSIS frames into a DEPI payload of the DEPI PW packets.

The DEPI is associated with a DEPI control plane and a separate DEPIdata plane. The DEPI control plane performs the following functions:session set up and tear down (e.g., for transports that require sessionsetup); PW set up and tear down (e.g., per channel); and reliablemessage delivery. The DEPI data plane performs data forwarding functions(e.g., forwarding DOCSIS frames encapsulated suitably for transport overnetwork 12).

Turning to UEPI, UEPI builds upon the DEPI PW concepts and uses avariation of the PSP encapsulation. The UEPI control plane is the sameas the DEPI control plane; the UEPI data plane is generally compatiblewith the DEPI data plane with some modifications that are outside thescope of this Specification. Moreover, UEPI and DEPI PW packet formatsare identical to the extent relevant to the disclosure of thisSpecification. Hence, wherever DEPI PW packets are referred to in thisSpecification, it may be noted that the description is equallyapplicable to UEPI PW packets without departing from the scope of theembodiments. In other words, the PW packets described in thisSpecification comprise DEPI PW packets, and/or UEPI PW packets.

In various embodiments, the PW packet format is modified to accommodateSR. In a general sense, SR leverages a source routing paradigm, in whicha node steers a packet through an ordered list of instructions, calledsegments (e.g., a segment can represent any instruction, topological orservice-based; a segment can have a local semantic to a node or have aglobal definition within an SR domain). SR allows enforcement of a flowthrough any topological path and service chain while maintainingper-flow state only at the ingress node to the SR domain.

SR may be implemented in MPLS networks or IPv6 networks suitably. SR isdirectly applied to the MPLS architecture with no change on theforwarding (data) plane. The segment is encoded as an MPLS label, withan ordered list of segments being encoded as a stack of labels. Thesegment to process is on the top of the stack. Upon completion ofprocessing the segment, the related label is decapsulated from the labelstack. SR is applied to the IPv6 architecture with a new type of routingheader. The segment is encoded as an IPv6 address, with an ordered listof segments being encoded as an ordered list of IPv6 addresses in therouting header. The segment to process is indicated by a destinationaddress of the packet. The next segment to process is indicated by apointer in the routing header.

In a general sense, the segment is identified by a segment identifier(PW SID), which may comprise an MPLS label in MPLS networks and IPV6address, in IP networks. Typically, the PW SIDs are advertised usinginterior gateway protocol (IGP) or border gateway protocol (BGP)extensions, such as Open Shortest Path First (OSPF) and IntermediateSystem to Intermediate System (IS-IS) protocols. Segment types cancomprise Node Segment, and Adjacency Segment.

In such SR enabled networks, RPD 16 cannot recognize or generate SRenabled packets because it does not have the requisite hardware (e.g.,application specific integrated circuits, network processors, etc.) forSR processing. However, according to embodiments of communication system10, a new type of segment, namely, PW Segment is defined that bindsforwarding behavior of PW packets to an attachment circuit (e.g., typeof L2-specific sublayer). The PW Segment includes instructions to map aDEPI or UEPI session identifier to the attachment circuit. Accordingly,RPD 16 can seamlessly run DEPI over L2TPv3 directly over SegmentRouting, for both MPLS and IPv6. Such SR enabled functionality canfacilitate various benefits, including application-based servicecreation, stateless-ness, resiliency (FRR), network simplification andhigher link utilization in network 12 for PW packets.

In some embodiments, CCAP-Core 14 and/or controller 22 configures RPD 16using appropriate configuration parameters in control messages to allowRPD 16 to identify SR information and format PW packets accordingly. Inan example embodiment, CCAP-Core 14 configures RPD 16 using GenericControl Plane (GCP) protocol. GCP allows control plane data structuresfrom other protocols to be tunneled through its generic control plane.For example, GCP can directly use DOCSIS type-lengths-values (TLVs) forthe configuration of RPD PHY parameters. Such configuration informationcan include segment routing information for various radio frequency (RF)parameters (e.g., DOCSIS profiles, QAM channels, etc.). Note that theDEPI and UEPI protocols also contain a certain amount of configurationinformation. In some embodiments, the DEPI and UEPI is focused onsession signaling, including segment routing information, and GCP isused for RPD-specific configuration and operation.

Communication system 10 is configured to address (among others) issuespertaining to communication over packet switched network 12 in a cablemodem network environment. Accordingly, RPD 16 receives, over packetswitched network 12, a PW control packet comprising segment routinginformation including a PW segment identifier (PW SID) for establishinga data session between RPD 16 and a network element, such as CCAP-Core14 over packet switched network 12. As used herein, the term ‘networkelement’ is meant to encompass components of a network, including acable network, with components such as CMTS, CCAP-Core 14, and cablemodem 18, any of which may be implemented as computers, networkappliances, servers, routers, switches, gateways, bridges,load-balancers, firewalls, processors, modules, or any other suitabledevice, component, element, or object operable to exchange informationaccording to DOCSIS standards. Moreover, the network elements mayinclude any suitably configured hardware provisioned with suitablesoftware, components, modules, interfaces, or objects that facilitatethe operations thereof. This may be inclusive of appropriate algorithmsand communication protocols that allow for the effective exchange ofdata or information.

The PW SID received at RPD 16 is indicative of a segment in packetswitched network 12 to be used for communicating PW data packets of thedata session. RPD 16 writes into a segment table therein a mappingbetween the PW SID and the data session. Note that in variousembodiments, the data session is associated with particular radiofrequency parameters for communication between RPD 16 and cable modem18, with the mapping (written into the segment table) associating theparticular radio frequency parameters and the PW SID.

RPD 16 receives data from another network element, such as cable modem18, over another network, such as HFC network 20, the data beingassociated with the data session between RPD 16 and CCAP-Core 14. RPD 16looks up the segment table for the PW SID using information identifyingthe data session, generates a PW data packet, comprising a segmentrouting header having the PW SID, and transmitting the PW data packetover packet switched network 12 to CCAP-Core 14.

In some embodiments, RPD 16 receives a PW data packet from CCAP-Core 14,the PW data packet having the PW SID information in a segment routingheader of the PW data packet, the PW data packet including a payloadwith data destined to cable modem 18. RPD 16 decapsulates the PW datapacket, looks up the segment table using the PW SID for the datasession, generates radio frequency signals having the data according toradio frequency parameters of the data session, and transmits the radiofrequency signals over coaxial (HFC) network 20 to cable modem 18.

In various embodiments, the segment routing information is provided inan attribute value pair (AVP) portion of a header of the PW controlpacket. Note that if IPv6 protocol is used for communication in packetswitched network 12, the PW SID comprises a destination IPv6 addressidentifying the segment. If MPLS protocol is used for communication inpacket switched network 12, wherein the PW SID comprises a MPLS labelstack identifying the segment. The PW control packet comprises aspecific combination of a DEPI header and a L2TPv3 header, the PW SIDassociating the specific combination with the MPLS label stack. Thesegment routing information can include another PW SID associated with atunnel between RPD 16 and CCAP-Core 14, with multiple data sessions pertunnel. Note that the segment routing information is distributed to RPD16 without IGP and BGP. Rather, the segment routing information isdistributed to RPD 16 according to DEPI over L2TPv3.

Turning to the infrastructure of communication system, the cable modemnetwork can include any number of cable modems, customer premisesequipment, servers, switches (including distributed virtual switches),routers, and other nodes inter-connected to form a large and complexnetwork that supports cable modem protocols such as DOCSIS. Inparticular, the cable modem network comprises cable modems distributedin various geographic locations, communicatively coupled over radiofrequency communication to one or more RPD 16, which in turncommunicates with CCAP-Core 14.

In a general sense, the network also represents a series of points ornodes of interconnected communication paths for receiving andtransmitting packets and/or frames of information that are delivered tothe communication system. A node may be any electronic device, computer,printer, hard disk drive, client, server, peer, service, application, orother object capable of sending, receiving, or forwarding informationover communications channels in a network. Elements of FIG. 1 may becoupled to one another through one or more interfaces employing anysuitable connection (wired or wireless), which provides a viable pathwayfor electronic communications. Additionally, any one or more of theseelements may be combined or removed from the architecture based onparticular configuration needs.

The network offers a communicative interface between cable modem networkcomponents, and may include any local area network (LAN), wireless localarea network (WLAN), metropolitan area network (MAN), Intranet,Internet, Extranet, wide area network (WAN), virtual private network(VPN), or any other appropriate architecture or system that facilitatescommunications in a network environment. Network 12 may implement anysuitable communication protocol for transmitting and receiving PW datapackets within the communication system. The architecture of the presentdisclosure may include a configuration capable of TCP/IP, TDMA, and/orother communications for the electronic transmission or receptioninformation in a network. The architecture of the present disclosure mayalso operate in conjunction with any suitable protocol, whereappropriate and based on particular needs. In addition, gateways,routers, switches, and any other suitable nodes (physical or virtual)may be used to facilitate electronic communication between various nodesin the network.

Note that the numerical and letter designations assigned to the elementsof FIG. 1 do not connote any type of hierarchy; the designations arearbitrary and have been used for purposes of teaching only. Suchdesignations should not be construed in any way to limit theircapabilities, functionalities, or applications in the potentialenvironments that may benefit from the features of the communicationsystem. It should be understood that the communication system shown inFIG. 1 is simplified for ease of illustration.

In some embodiments, a communication link may represent any electroniclink supporting a network environment such as, for example, cable,Ethernet, wireless technologies (e.g., IEEE 802.11x), ATM, fiber optics,etc. or any suitable combination thereof. In other embodiments,communication links may represent a remote connection through anyappropriate medium (e.g., digital subscriber lines (DSL), telephonelines, T1 lines, T3 lines, wireless, satellite, fiber optics, cable,Ethernet, etc. or any combination thereof) and/or through any additionalnetworks such as a wide area networks (e.g., the Internet).

In particular embodiments, RPD 16 may comprise suitable hardwarecomponents and interfaces for facilitating the operations describedherein. In some embodiments, RPD 16 may be embedded in or be part ofanother hardware component, such as a broadband processing engine(comprising a motherboard, microprocessors and other hardwarecomponents). In some embodiments, RPD 16 includes downstream andupstream PHY components, deployed in a Coaxial Media Converter (CMC)that supports RF functions at the PHY layer. In particular embodiments,CCAP-Core 14 may comprise a hardware appliance with appropriate ports,processors, memory elements, interfaces, and other electrical andelectronic components that facilitate the functions described herein.

RDP 16 includes hardware and software providing network functions on theMAC layer and PHY layer. The PHY layer is responsible for receiving andtransmitting RF signals. Hardware portions of the PHY layer includes atleast one upstream PHY and/or at least one downstream PHY. The PHY layeralso includes software for driving the hardware components of the PHYlayer. In a general sense, upstream optical data signals arriving viaoptical fiber over coaxial network 20 are converted to electricalsignals and then demodulated by the upstream PHY at RPD 16. Thedemodulated information is then passed to the MAC layer.

On the downstream side, PW packets arriving over packet switched network12 are transmitted by the MAC to the downstream PHY. At the downstreamPHY, the data in the packets are converted into modulated downstream RFframes using, for example, QAM64 modulation. Other methods of modulationmay also be used such as, for example, QAM256 modulation, CDMA (CodeDivision Multiple Access), OFDM (Orthogonal Frequency DivisionMultiplexing), FSK (FREQ Shift Keying), etc. The modulated data isconverted from intermediate frequency (IF) electrical signals to radiofrequency (RF) electrical signals (or vice-versa) using one or moreelectrical signal converters in RPD 16.

The MAC layer includes both a MAC hardware portion and a MAC softwareportion for upstream MAC and downstream MAC. The MAC layer hardware andsoftware portions operate together to provide the DOCSIS MACfunctionality. The MAC layer encapsulates, with MAC headers, downstreampackets at the downstream MAC and decapsulates the MAC headers ofupstream packets at the upstream MAC. The MAC headers include addressesto specific cable modem(s) 18 (if sent downstream), or to CCAP-Core 14(if sent upstream).

CCAP-Core 14 comprises hardware and software for enabling networkrouting, DOCSIS packet forwarding and other network functions of theCMTS. For example, the hardware and software modules in CCAP-Core 14includes a routing module, a forwarding module, a Data Over CableService Interface Specification (DOCSIS) control module, and one or moreline cards. The routing module and the DOCSIS control module form partof a control plane, whereas the forwarding module and the line cardsform part of a data plane. The routing module implements routing orforwarding operations in the control plane and the forwarding moduleprovides packet-forwarding operations in the data plane. Additionally,in some embodiments, CCAP-Core 14 also includes a utility componentadapted to provide a system clock and a timestamp functionality. Therouting module may provide layer one, layer two, layer three, and layerfour functionality, as well as quality of service (QoS) functionality.

CCAP-Core 14 may include functionalities found in a typical router, forexample, Cisco's uBR Universal Broadband Router, with a network routingoperating system. The routing module is configured to construct and loadrouting tables used by the forwarding module in CCAP-Core 14 and RPD 16.The routing module performs configuration management functions, such asdistributing the PW SID information, and communicates with neighboringpeer, standby, and/or backup routers to exchange protocol data unitsused to construct the routing tables applicable in packet switchednetwork 12 in accordance with routing algorithms. The DOCSIS controlmodule sends timing and frequency requirements to RPD 16 in suitableMedia Access Protocol (MAP) messages using DEPI over L2TPV3.

In various embodiments, controller 22 comprises an application executingin a network element (e.g., server, router, switch, etc.) of network 12.In some embodiments, controller 22 uses suitable protocols, such asOpenFlow, to configure RPD 16 appropriately. Typically, controller 22includes a collection of “pluggable” software modules that can performdifferent network tasks, such as inventorying what devices are withinnetwork 12 and the capabilities of each, gathering network statistics,etc. Extensions can be inserted that enhance the functionality andsupport more advanced capabilities, such as running algorithms toperform analytics and orchestrating new rules throughout network 12.Controller 22 includes an extension for generating control packetsaccording to DEPI/UEPI over L2TPv3 protocols with SR information andcommunicating the control packets to RPD 16.

In a general sense, DOCSIS 3.1, CCAP-Core 14, and RPD 16 changes thephysical infrastructure of typical cable networks having centralized MACand PHY functions (e.g., at a CMTS device). SDN and network functionvirtualization (NFV) virtual infrastructure together with DOCSIS 3.1,CCAP-Core 14, and RPD 16 can enable cable operators to provide moreflexible services and deliver services more quickly while also reducingcapital expenditure and operating costs. According to embodiments ofcommunication system 10, many of the components used to construct andsupport base service functions of network 12 may continue to execute indedicated platforms outside the NFV environment. In the cable operatornetwork this could include elements such as the routing and switchinginfrastructure, CCAP-Core platforms, and the Remote-PHY equipment.Components associated with service and management functions are migratedfrom dedicated servers and platforms toward the NFV environment. Thisincludes network control elements (Dynamic Host Configuration Protocol(DHCP), packet cable multimedia (CMM), SR information, and so on) andappliances (firewall, deep packet inspection (DPI), and Network AddressTranslation (NAT)). In various embodiments, controller 22 determines thesegments to be used for various data sessions between CCAP-Core 14 andRPD 16, and communicates the segment routing information in appropriatecontrol packets to RPD 16.

Turning to FIG. 2, FIG. 2 is a simplified block diagram illustrating anexample implementation of communication system 10. A control connection24, also called a PW tunnel, is established between CCAP-Core 14 and RPD16. Control connection 24 allows for PW control packets 26 to be sentbetween CCAP-Core 14 and RPD 16. Typical PW control packets 26 set upmore than one data session 30 (e.g., one for each downstream QAMchannel) between CCAP-Core 14 and RPD 16. Within the PW tunnel ofcontrol connection 24, separate PWs consisting of more than one L2TPv3data session 30 may be active for each MAC-PHY functional pair. The dataplane encapsulation is managed per data session 30. Depending upon thetype of PW encapsulation used, a PW may contain one or more channels.

Each data session 30 can be marked with different DifferentiatedServices Code Points (DSCPs) and can support different encapsulationprotocols. Each data session 30 can include one or more data flows 32for communicating PW data packets. In the example shown in the figure,two sessions, namely, Session A and Session B are shown. Each of SessionA and Session B are indicated with two flows, Flow 1 and Flow 2. Anynumber of sessions and flows therein may be active at any time betweenCCAP-Core 14 and RPD 16 within the broad scope of the embodiments. Eachof data flows 32 comprises PW data packets 34. Each of PW data packets34 contains a 32-bit session identifier (ID) identifying the specificdata session associated with the PW data packet. At RPD 16, PW datapackets 34 are decapsulated and converted to the RF domain, andtransmitted to CM 18 on respective RF Channels 36.

In many embodiments, PW control packets 26 and PW data packets 34 aresubstantially identical in format, including number and types ofheaders, and fields included in respective headers; PW control packets26 and PW data packets 34 are differentiated based on particular valuesof fields in respective headers. For example, a session ID field in aL2TPv3 header of PW control packets 26 has zero values for PW controlpackets 26, and non-zero values for PW data packets 34, differentiatingthem from each other. Note that PW control packets 26 and PW datapackets 34 comprise PW packets, in a general sense. In other words, theterm “PW packet” refers to PW control packets 26 and/or PW data packets34 interchangeably, unless and otherwise specified.

Turning to FIG. 3, FIG. 3 is a simplified block diagram illustratingexample details of PW packets according to an embodiment ofcommunication system 10. L2TPv3 permits creating a sub-header in thepacket headers of PW packets, whose definition is specific to thepayload being carried. In a general sense, PW control packets 26 and/orPW data packets 34 may comprise a format as indicated with a pluralityof headers. According to an example embodiment, rather thanre-implementing DEPI protocols on MPLS and rather than converting theDEPI control plane to MPLS-TE, MPLS can be used as a tunnel underneaththe DEPI tunnel. Thus, none of the DEPI signaling is re-written. Rather,the DEPI signaling using L2TPv3 is augmented with new DEPI AVPs added toexisting DEPI PW formats that would associate a DEPI/L2TPv3 session witha Segment Routing Segment ID (and header), both to be used with MPLSlabels or IPv6 header extensions.

Accordingly, PW control packets 26 and PW data packets 34 comprise thefollowing headers stacked one over the other: Ethernet header; SR header38; L2TPv3 header; R-PHY header; payload; and cyclic redundancy check(CRC) field. In some embodiments, wherein PW packets are communicatedover an IPv6 network, SR header 38 comprises IP header 39; in otherwords, IP header 39 functions as SR header 38, having appropriate SRrelated extensions (e.g., fields and values) therein. In someembodiments, wherein PW packets are communicated over an MPLS network,SR header 38 comprises MPLS header 40; in other words, MPLS header 40functions as SR header 38, having appropriate SR related extensions(e.g., MPLS label stack) therein. Note that PW control packets 26comprises a DEPI header over L2TPv3 with the PW SID in SR header 38(e.g., MPLS header 40 or IPv6 header 39); PW data packets 34 comprises aUEPI header over L2TPv3 with the PW SID in its SR header.

Turning to FIG. 4, FIG. 4 is a simplified block diagram illustratingexample details of PW packets (e.g., PW control packets 26 and/or PWdata packets 34) according to an embodiment of communication system 10.An attribute-value-pair (AVP) encodes a PW segment identifier (PW SID)in a SID AVP 42. Flags specify a type of PW SID (e.g., PW SID vs. Label,and Relative vs. Absolute value (PW SID vs. Index)). SID AVP 42 isincluded in incoming call request (ICRQ), and outgoing call request(OCRQ) messages in some embodiments. SID AVP 42 is bound to a particularone of data session 30. Further, a non-zero value for SID AVP 42 denoteswillingness to run SR for that data session 30. In various embodiments,the general header format leverages the CableLabs™ Enterprise NumberVendor ID of 4491 (which may also be used by messages according to GCP).

Alternatively, the PW SID value of SID AVP 42 may indicate binding ofdata session 30 to a whole tunnel, e.g., comprising one controlconnection (e.g., session) 24 and multiple data session 30. In yetanother embodiment, SID AVP 42 may include a Tunnel PW SID and a Service(Session) PW SID, both advertised over L2TPv3. In yet anotherembodiment, SR header 38 may comprise a stack of two segments, onesegment corresponding to the Tunnel PW SID, and the other segmentcorresponding to the particular data session PW SID.

Embodiments of communication system 10 provide for SID AVP 42 comprisinga new PW Segment (which is also called a Tunnel Segment), which is adifferent type of segment than typical Node Segment and AdjacencySegment of SR enabled networks. (Node Segment represents a node havingglobal significance in the network, wherein every node in a SR domaininstalls an MPLS label (or IPV6 address) in the data plane representingthe node segment; Adjacency Segment represents a link and has localsignificance relevant to the nodes directly connected by the link).

The PW Segment Type binds forwarding behavior to an attachment circuit(e.g., attachment circuit comprises the physical or virtual circuit innetwork 12 attaching CM 18 to CCAP-Core 14). The attachment circuit cancomprise a type of L2-Specific Sublayer, unique to DOCSIS PWcommunication; for example, the attachment circuit comprises a binding(e.g., through appropriate PW mapping in a database) between a specificnetwork segment in network 12 and a particular CM (or group of CMs). ThePW Segment Type also includes an adaptation layer specifyingcharacteristics of the attachment circuit, for example, including asegment instruction to map a session ID (of data session 30) to theattachment circuit. Moreover, the PW Segment can be applied withindifferent layers to DEPI, specifically at the L2TPv3 Tunnel or theL2TPv3 Session levels.

In various embodiments, there is no direct integration of SR andDEPI/L2TPv3, because typical SR protocols remove control planes that setup labels (LDP, RSVP), and relies on IGP (OSPF, IS-IS) or BGP todistribute segments, because SR advertises segments in a typical SRenabled network using IGP or BGP. However, there is no IGP or BGP in thecontext of DEPI or UEPI. SR gets set up before the L2TPv3 controlconnection. Moreover, discovery and advertisement mechanisms accordingto embodiments described herein with protocols such as GCP or DEPI (bothinherently different to an IGP flooding or a BGP reflector) aredifferent from the mechanisms used with IGP or BGP.

In various embodiments, SR information may be set up with GCP or withDEPI. In an example embodiment, the format as indicated in the figurecan be implemented with GCP. This is particularly interesting in thecable use case because network 12 may comprise a Metro Ethernet Networkin an access portion and routing protocols may not be normally run. Todate, DEPI control plane is used to setup networking relatedconfiguration and GCP is used for setting up MAC and PHY relatedconfiguration. SR falls somewhere in between GCP and DEPI. GCP can be agood configuration choice because GCP is the general purposeconfiguration interface. Even longer term with something like WAE, asegment can be bound to an attachment circuit according to someembodiments.

According to some embodiments, communication system 10 implementing theDEPI over MPLS or IPV6 formats includes an ability to advertise (anddiscover) segments with either GCP or with DEPI, in the absence of IGPor a BGP, using GCP or DEPI to enable both native IPv6 or MPLS SR, aspart of an initial configuration negotiation, and an ability to set up apair of segments on the segment stack using GCP or DEPI. In addition,the method also includes association of Application and PW segments inthe stack and allows L2TPv3 native to directly run on top of MPLS. Notethat the mechanisms disclosed herein can also be extended to varioustunneling types, with DEPI being an example deployment.

Turning to FIG. 5, FIG. 5 is a simplified block diagram illustratingexample details according to an embodiment of communication system 10.In various embodiments, CCAP-Core 14, or alternatively, controller 22,communicates to RPD 16, PW control packets 26 comprising SID AVP 42having an appropriate PW Segment identifier (PW SID). The PW SID binds aspecific network segment in network 12 to communication betweenCCAP-Core 14 and one or more CM 18, for example, through specific RFChannels 36. For example, PW SID 1 may bind RF channel 1 to segment S1in network 12; PW SID 2 may bind RF channel 2 to segment S2 in network12; and so on.

RPD 16 includes a processor 44, a memory element 46 (both of which maybe included in a single central processing unit (CPU) in someembodiments), an Ethernet interface 48, one or more PHY units 50, andone or more output interfaces 52, corresponding to separate RF Channels36. PW control packets 26 comprising SID AVP 42 is received at RPD 16over Ethernet interface 48. RPD 16 decapsulates PW control packets 26and writes the association indicated by SID AVP 42 to a Segment Table54. Further, data sessions 30 may be established, and other actionsaccording to PW control packets 26 may be performed suitably.

On the upstream side, RF signals are received at Output Interface 52over coaxial network 20 through RF channel 36. At PHY Unit 50, thereceived RF signals are digitized, demodulated, and DOCSIS frames areextracted from the Forward Error Correction (FEC) payload. The DOCSISframes are placed into a suitable UEPI encapsulation corresponding tothe data session. A PW data packet Generator 56 looks up Segment Table54, and generates an appropriate PW header for the received data,including SR header 38, with appropriate values for SID AVP 42. The datais formatted into PW data packets 34 and sent over network 12 toCCAP-Core 14. The communication over network 12 follows segment routingprotocols according to the segment information indicated in SR header 38of PW data packets 34. A clocking circuit manages clocking and timingaccuracy for RPD 16. A local CPU comprising processor 44 and memoryelement 46 manages the DEPI (and UEPI) and Generic Control Plane (GCP)control planes and provides an interface into network management.

On the downstream side, PW data packets 34 arrive from CCAP-Core 14 onEthernet interface 48. At PHY Unit 50, the DEPI framing is terminated;the PW headers are decapsulated and the payload is extracted. The PW SIDfrom SID AVP 42 is identified. PW data packet Generator 56 looks upSegment Table 54 using the PW SID for appropriate RF parametersassociated with the data session mapped to the PW SID. The payload isaccordingly suitably modulated, and transmitted out through OutputInterface 52.

Turning to FIG. 6, FIG. 6 is a simplified block diagram illustratingexample details of mapping according to an embodiment of communicationsystem 10. RPD 16 includes Segment Table 54. In some embodiments,Segment Table 54 includes a tunnel to channel mapping 60; for example,tunnel to channel mapping 60 specifies an association between tunnelsand RF Channels (e.g., Tunnel 1 having PW SID 1 mapped to RF Channel 1;Tunnel 2 having PW SID 2 mapped to RF Channel 2; and so no). In someembodiments, Segment Table 54 includes a tunnel to session mapping 62;for example, Tunnel 1 having PW SID 1 mapped to Session A; Tunnel 2having PW SID 2 mapped to Session B; and so on. In some embodiments,Segment Table 54 includes a tunnel to profile mapping 64; for example,Tunnel 1 having PW SID 1 mapped to Profile A; Tunnel 2 having PW SID 2mapped to Profile B; and so on. (DOCSIS protocols allow differentquality of service and/or modulated communication through differentprofiles). In a general sense, packet switched network 12 may comprise Ntunnels 66 mapped to, or communicating data from (or to) M RF Channels36. Tunnels 66 route PW packets between CCAP-Core 14 and RPD 16 overnetwork 12.

Turning to FIG. 7, FIG. 7 is a simplified flow diagram illustratingexample operations 100 that may be associated with embodiments ofcommunication system 10. At 102, control session (e.g., connection) 24may be established between CCAP-Core 14 (or controller 22) and RPD 16.At 104, PW control packets 26 comprising SID AVP 42 may be received atRPD 16. At 106, the received PW SID may be mapped into Segment Table106, for example associating a specific tunnel with one of RF Channels36 according to the mapping indicated in PW control packets 26.Thereafter, data may be received at RPD 16 from CCAP-Core 14 overnetwork 12 and/or CM 18 over RF Channels 36.

Turning to data received from CCAP-Core 14, at 108, data is received atRPD 16 from CCAP-Core 14, for example, in data session 30, in the formof PW data packets 34. At 110, RPD 16 decapsulates headers, including SRheader 38 from PW data packets 34. The decapsulating process extractsthe PW SID in SR header 38. At 112, RF parameters (e.g., RF Channel,frequencies, etc.) may be determined from information in Segment Table54 corresponding to the extracted PW SID. At 114, a suitable RF signalincorporating the received DOCSIS data (or video) may be generated andtransmitted at 116 to the appropriate cable modem(s) 18.

Turning to data received from cable modem(s) 18, at 118, data may bereceived over one of RF Channels 36. At 120, the relevant tunnel for thedata may be determined from information in Segment Table 54corresponding to the data type or RF interface (and/or other RFparameters, as appropriate). At 122, PW data packet Generator 56generates PW data packets 34 with appropriate SR header 38 having therelevant SR information (PW SID, etc.). At 124, PW data packets 34 aretransmitted to CCAP-Core 14 over network 12 according to SR protocols.

Note that in this Specification, various components of communicationsystem 10 reference cable networks. However, the operations describedherein, and the packet header formats, are applicable in general to manydifferent types of networks. For example, communication system 10 cancomprise an Internet of Things (IOT), with RPD 16 comprising one or more“dumb” devices, such as sensors that merely collect data without furtherprocessing. For example, RPD 16 comprises a medical sensor that senses aperson's pulse and oxygen levels and transmits the data over network 12to a receiving CCAP-Core 14, comprising a medical informationserver/database in a hospital. In another example, RPD 16 comprises abarometer that collects atmospheric pressure data and transmits the dataover network 12 to a receiving CCAP-Core 14, comprising a weatherserver. In yet another example, RPD 16 comprises a location sensor thattransmits a vehicle's location relative to a geostationary satellite andtransmits the data over network 12 to a receiving CCAP-Core 14,comprising a location server/database. In all such examples, it is notnecessary that RPD 16 be configured with sophisticated networkprocessors for transmitting the data. According to the variousembodiments described herein, the data may be encapsulated inappropriate SR header 38 comprising the SR information of network 12 andcommunicated over network 12 using simple interfaces and packetgenerators in RPD 16 using RPD 16's native data communication protocols.

Note that in this Specification, references to various features (e.g.,elements, structures, modules, components, steps, operations,characteristics, etc.) included in “one embodiment”, “exampleembodiment”, “an embodiment”, “another embodiment”, “some embodiments”,“various embodiments”, “other embodiments”, “alternative embodiment”,and the like are intended to mean that any such features are included inone or more embodiments of the present disclosure, but may or may notnecessarily be combined in the same embodiments. Furthermore, the words“optimize,” “optimization,” and related terms are terms of art thatrefer to improvements in speed and/or efficiency of a specified outcomeand do not purport to indicate that a process for achieving thespecified outcome has achieved, or is capable of achieving, an “optimal”or perfectly speedy/perfectly efficient state.

In example implementations, at least some portions of the activitiesoutlined herein may be implemented in software. In some embodiments, oneor more of these features may be implemented in hardware, providedexternal to these elements, or consolidated in any appropriate manner toachieve the intended functionality. The various components may includesoftware (or reciprocating software) that can coordinate in order toachieve the operations as outlined herein. In still other embodiments,these elements may include any suitable algorithms, hardware, software,components, modules, interfaces, or objects that facilitate theoperations thereof.

Furthermore, RPD 16 described and shown herein (and/or their associatedstructures) may also include suitable interfaces for receiving,transmitting, and/or otherwise communicating data or information in anynetwork environment. Additionally, some of the processors and memoryelements associated with the various network nodes may be removed, orotherwise consolidated such that a single processor and a single memoryelement are responsible for certain activities. In a general sense, thearrangements depicted in the FIGURES may be more logical in theirrepresentations, whereas a physical architecture may include variouspermutations, combinations, and/or hybrids of these elements. It isimperative to note that countless possible design configurations can beused to achieve the operational objectives outlined here. Accordingly,the associated infrastructure has a myriad of substitute arrangements,design choices, device possibilities, hardware configurations, softwareimplementations, equipment options, etc.

In some of example embodiments, one or more memory elements (e.g.,memory elements 46) can store data used for the operations describedherein. This includes the memory element being able to storeinstructions (e.g., software, logic, code, etc.) in non-transitorymedia, such that the instructions are executed to carry out theactivities described in this Specification. A processor (e.g., processor44) can execute any type of instructions associated with the data toachieve the operations detailed herein in this Specification. In oneexample, processors could transform an element or an article (e.g.,data) from one state or thing to another state or thing. In anotherexample, the activities outlined herein may be implemented with fixedlogic or programmable logic (e.g., software/computer instructionsexecuted by a processor) and the elements identified herein could besome type of a programmable processor, programmable digital logic (e.g.,a field programmable gate array (FPGA), an erasable programmable readonly memory (EPROM), an electrically erasable programmable read onlymemory (EEPROM)), an ASIC that includes digital logic, software, code,electronic instructions, flash memory, optical disks, CD-ROMs, DVD ROMs,magnetic or optical cards, other types of machine-readable mediumssuitable for storing electronic instructions, or any suitablecombination thereof.

These devices may further keep information in any suitable type ofnon-transitory storage medium (e.g., random access memory (RAM), readonly memory (ROM), field programmable gate array (FPGA), erasableprogrammable read only memory (EPROM), electrically erasableprogrammable ROM (EEPROM), etc.), software, hardware, or in any othersuitable component, device, element, or object where appropriate andbased on particular needs. The information being tracked, sent,received, or stored in the communication system could be provided in anydatabase, register, table, cache, queue, control list, or storagestructure, based on particular needs and implementations, all of whichcould be referenced in any suitable timeframe. Any of the memory itemsdiscussed herein should be construed as being encompassed within thebroad term ‘memory element.’ Similarly, any of the potential processingelements, modules, and machines described in this Specification shouldbe construed as being encompassed within the broad term ‘processor.’

It is also important to note that the operations and steps describedwith reference to the preceding FIGURES illustrate only some of thepossible scenarios that may be executed by, or within, the system. Someof these operations may be deleted or removed where appropriate, orthese steps may be modified or changed considerably without departingfrom the scope of the discussed concepts. In addition, the timing ofthese operations may be altered considerably and still achieve theresults taught in this disclosure. The preceding operational flows havebeen offered for purposes of example and discussion. Substantialflexibility is provided by the system in that any suitable arrangements,chronologies, configurations, and timing mechanisms may be providedwithout departing from the teachings of the discussed concepts.

Although the present disclosure has been described in detail withreference to particular arrangements and configurations, these exampleconfigurations and arrangements may be changed significantly withoutdeparting from the scope of the present disclosure. For example,although the present disclosure has been described with reference toparticular communication exchanges involving certain network access andprotocols, the communication system may be applicable to other exchangesor routing protocols. Moreover, although the communication system hasbeen illustrated with reference to particular elements and operationsthat facilitate the communication process, these elements, andoperations may be replaced by any suitable architecture or process thatachieves the intended functionality of the communication system.

Numerous other changes, substitutions, variations, alterations, andmodifications may be ascertained to one skilled in the art and it isintended that the present disclosure encompass all such changes,substitutions, variations, alterations, and modifications as fallingwithin the scope of the appended claims. In order to assist the UnitedStates Patent and Trademark Office (USPTO) and, additionally, anyreaders of any patent issued on this application in interpreting theclaims appended hereto, Applicant wishes to note that the Applicant: (a)does not intend any of the appended claims to invoke paragraph six (6)of 35 U.S.C. section 112 as it exists on the date of the filing hereofunless the words “means for” or “step for” are specifically used in theparticular claims; and (b) does not intend, by any statement in thespecification, to limit this disclosure in any way that is not otherwisereflected in the appended claims.

What is claimed is:
 1. A method comprising: receiving, at a remotephysical device (RPD), a pseudowire (PW) control packet comprisingsegment routing information including a PW segment identifier (PW SID)for establishing a data session between the RPD and a network elementover a packet switched network, the PW SID indicative of a segment inthe packet switched network to be used for communicating PW data packetsof the data session, the PW control packet and the PW data packetsrespectively carrying control information and data, and comprisingemulations of a point-to-point connection over the packet switchednetwork between the RPD and the network element; and writing into asegment table of the RPD a mapping between the PW SID and the datasession.
 2. The method of claim 1, further comprising: receiving, at theRPD, data from another network element over another network, wherein thedata is associated with the data session between the RPD and the networkelement; looking up the segment table for the PW SID using informationidentifying the data session; generating a PW data packet, comprising asegment routing header having the PW SID; and transmitting the PW datapacket over the packet switched network to the network element.
 3. Themethod of claim 2, wherein the another network comprises a hybrid fibercoaxial network for radio frequency signals, wherein the another networkelement comprises a cable modem.
 4. The method of claim 2, wherein thedata session is associated with particular radio frequency parametersfor communication between the RPD and the another network element,wherein the mapping comprises an association between the particularradio frequency parameters and the PW SID.
 5. The method of claim 1,further comprising: receiving, at the RPD, a PW data packet from thenetwork element, the PW data packet having the PW SID information in asegment routing header of the PW data packet, the PW data packetcomprising data destined to another network element in another network;decapsulating the PW data packet; looking up the segment table using thePW SID for the data session; generating radio frequency signalscomprising the data according to radio frequency parameters of the datasession; and transmitting the radio frequency signals over the anothernetwork to the another network element.
 6. The method of claim 1,wherein the segment routing information is provided in an attributevalue pair (AVP) portion of a header of the PW control packet.
 7. Themethod of claim 1, wherein the network element comprises a ConvergedCable Access Platform (CCAP) Core of a cable network.
 8. The method ofclaim 1, wherein Internet Protocol version 6 (IPv6) protocol is used forcommunication in the packet switched network, wherein the PW SIDcomprises a destination IPv6 address identifying the segment.
 9. Themethod of claim 1, wherein Multi-Protocol Label Switching (MPLS)protocol is used for communication in the packet switched network,wherein the PW SID comprises a MPLS label stack identifying the segment.10. The method of claim 9, wherein the PW control packet comprises aspecific combination of a downstream external physical interface (DEPI)header and a Layer 2 Tunneling Protocol Version 3 (L2TPv3) header,wherein the PW SID associates the specific combination with the MPLSlabel stack.
 11. The method of claim 1, wherein the segment routinginformation comprises another PW SID, wherein the another PW SID isassociated with a tunnel between the RPD and the network element, withmultiple data sessions per tunnel.
 12. The method of claim 1, whereinthe segment routing information is distributed to the RPD withoutInterior Gateway Protocols and Border Gateway Protocols.
 13. The methodof claim 1, wherein the segment routing information is distributed tothe RPD according to DEPI over L2TPv3.
 14. Non-transitory tangiblecomputer readable media that includes instructions for execution, whichwhen executed by a processor of a RPD, performs operations comprising:receiving, at the RPD, a PW control packet comprising segment routinginformation including a PW SID for establishing a data session betweenthe RPD and a network element over a packet switched network, the PW SIDindicative of a segment in the packet switched network to be used forcommunicating PW data packets of the data session, the PW control packetand the PW data packets respectively carrying control information anddata, and comprising emulations of a point-to-point connection over thepacket switched network between the RPD and the network element; andwriting into a segment table of the RPD a mapping between the PW SID andthe data session.
 15. The media of claim 14, the operations furthercomprising: receiving, at the RPD, data from another network elementover another network, wherein the data is associated with the datasession between the RPD and the network element; looking up the segmenttable for the PW SID using information identifying the data session;generating a PW data packet, comprising a segment routing header havingthe PW SID; and transmitting the PW data packet over the packet switchednetwork to the network element.
 16. The media of claim 14, theoperations further comprising: receiving, at the RPD, a PW data packetfrom the network element, the PW data packet having the PW SIDinformation in a segment routing header of the PW data packet, the PWdata packet comprising data destined to another network element inanother network; decapsulating the PW data packet; looking up thesegment table using the PW SID for the data session; generating radiofrequency signals comprising the data according to radio frequencyparameters of the data session; and transmitting the radio frequencysignals over the another network to the another network element.
 17. Themedia of claim 14, wherein the network element comprises a CCAP-Core ofa cable network.
 18. An apparatus, comprising: a memory element forstoring data; and a processor, wherein the processor executesinstructions associated with the data, wherein the processor and thememory element cooperate, such that the apparatus is configured for:receiving, at the apparatus, a PW control packet comprising segmentrouting information including a PW SID for establishing a data sessionbetween the RPD and a network element over a packet switched network,the PW SID indicative of a segment in the packet switched network to beused for communicating PW data packets of the data session, the PWcontrol packet and the PW data packets respectively carrying controlinformation and data, and comprising emulations of a point-to-pointconnection over the packet switched network between the RPD and thenetwork element; and writing into a segment table of the apparatus amapping between the PW SID and the data session.
 19. The apparatus ofclaim 18, wherein the apparatus is further configured for: receiving, atthe apparatus, data from another network element over another network,wherein the data is associated with the data session between theapparatus and the network element; looking up the segment table for thePW SID using information identifying the data session; generating a PWdata packet, comprising a segment routing header having the PW SID; andtransmitting the PW data packet over the packet switched network to thenetwork element.
 20. The apparatus of claim 18, wherein the apparatus isfurther configured for: receiving, at the apparatus, a PW data packetfrom the network element, the PW data packet having the PW SIDinformation in a segment routing header of the PW data packet, the PWdata packet comprising data destined to another network element inanother network; decapsulating the PW data packet; looking up thesegment table using the PW SID for the data session; generating radiofrequency signals comprising the data according to radio frequencyparameters of the data session; and transmitting the radio frequencysignals over the another network to the another network element.